Catalytical synthesis of internal fluorobutenes and internal fluoropentenes

ABSTRACT

A vapor phase process is disclosed for making internal fluorobutenes. The process involves contacting a halobutane starting material selected from the group consisting of CF 2 HCHClCH 2 CCl 2 H, CF 2 HCHClCH 2 CCl 3 , CF 3 CHClCH 2 CCl 2 H, CF 3 CHClCH 2 CCl 3 , CF 3 CHClCHClCCl 2 H, CF 3 CHClCHClCCl 3 , CF 3 CCl 2 CH 2 CCl 2 H, CF 3 CCl 2 CH 2 CCl 3 , CF 3 CCl 2 CHClCCl 2 H, CF 3 CCl 2 CHClCCl 3 , CF 3 CClFCHClCCl 2 H, CF 3 CClFCHClCCl 3 , CF 3 CClFCH 2 CCl 2 H, CF 3 CClFCH 2 CCl 3 , CF 3 CClFCHFCCl 2 H, CF 3 CClFCHFCCl 3 , CF 3 CClHCHFCCl 2 H and CF 3 CClHCHFCCl 3 , with HF in a reaction zone in the presence of a chromium oxyfluoride catalyst to produce a product mixture comprising an internal fluorobutene. Another vapor phase process is disclosed for making internal fluoropentenes. The process involves contacting a halopentane starting material selected from the group consisting of CF 2 HCHXCH 2 CX 2 CX 3 , CF 3 CHXCH 2 CX 2 CX 3 , CF 3 CHXCHXCX 2 CX 3 , CF 3 CX 2 CH 2 CX 2 CX 3 , CF 3 CX 2 CHXCX 2 CX 3  and CF 3 CHXCHFCX 2 CX 3 , with HF in a reaction zone in the presence of a chromium oxyfluoride catalyst to produce a product mixture comprising an internal fluoropentene, wherein each X is independently selected from the group consisting of F, Cl and Br, provided that not all X are fluorines.

BACKGROUND

1. Field of the Disclosure

This disclosure relates in general to the preparation of internalfluorobutenes and internal fluoropentenes using halobutanes andhalopentanes as starting materials respectively in vapor phase processescatalyzed by chromium oxyfluoride.

2. Description of Related Art

CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons) havebeen employed in a wide range of applications, including their use asaerosol propellants, refrigerants, cleaning agents, expansion agents forthermoplastic and thermoset foams, heat transfer media, gaseousdielectrics, fire extinguishing and suppression agents, power cycleworking fluids, polymerization media, particulate removal fluids,carrier fluids, buffing abrasive agents, and displacement drying agents.Due to the belief that CFCs and HCFCs are contributing to depletion ofstratospheric ozone, there has been extensive work in the past twodecades on replacement of these materials with non-ozone depletingsubstances. Hydrofluorocarbons (HFCs), which do not contain chlorine,have replaced CFCs and HCFCs in a number of applications. Although HFCsdo not contribute to the destruction of stratospheric ozone, they are ofconcern due to their potential contribution to the “greenhouse effect”(global warming). Thus, there is a need for compositions in theapplications noted above that do not contribute to the destruction ofstratospheric ozone and also have low global warming potentials (GWPs).Certain hydrofluoroolefins, such as internal fluorobutenes and internalfluoropentenes in this disclosure, are believed to meet both goals.

BRIEF SUMMARY OF THE DISCLOSURE

The present disclosure provides a vapor phase process to make internalfluorobutenes. The process comprises contacting a halobutane startingmaterial selected from the group consisting of CF₂HCHClCH₂CCl₂H,CF₂HCHClCH₂CCl₃, CF₃CHClCH₂CCl₂H, CF₃CHClCH₂CCl₃, CF₃CHClCHClCCl₂H,CF₃CHClCHClCCl₃, CF₃CCl₂CH₂CCl₂H, CF₃CCl₂CH₂CCl₃, CF₃CCl₂CHClCCl₂H,CF₃CCl₂CHClCCl₃, CF₃CClFCHClCCl₂H, CF₃CClFCHClCCl₃, CF₃CClFCH₂CCl₂H,CF₃CClFCH₂CCl₃, CF₃CClFCHFCCl₂H, CF₃CClFCHFCCl₃, CF₃CClHCHFCCl₂H andCF₃CClHCHFCCl₃, with HF in a reaction zone in the presence of a chromiumoxyfluoride catalyst to produce a product mixture comprising an internalfluorobutene.

The present disclosure also provides a vapor phase process to makeinternal fluoropentenes. The process comprises contacting a halopentanestarting material selected from the group consisting ofCF₂HCHXCH₂CX₂CX₃, CF₃CHXCH₂CX₂CX₃, CF₃CHXCHXCX₂CX₃, CF₃CX₂CH₂CX₂CX₃,CF₃CX₂CHXCX₂CX₃ and CF₃CHXCHFCX₂CX₃, with HF in a reaction zone in thepresence of a chromium oxyfluoride catalyst to produce a product mixturecomprising an internal fluoropentene, wherein each X is independentlyselected from the group consisting of F, Cl and Br, provided that notall X are fluorines.

DETAILED DESCRIPTION

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims. Other features andbenefits of any one or more of the embodiments will be apparent from thefollowing detailed description, and from the claims.

Disclosed is a vapor phase process for making internal fluorobutenescomprising contacting a halobutane starting material selected from thegroup consisting of CF₂HCHClCH₂CCl₂H, CF₂HCHClCH₂CCl₃, CF₃CHClCH₂CCl₂H,CF₃CHClCH₂CCl₃, CF₃CHClCHClCCl₂H, CF₃CHClCHClCCl₃, CF₃CCl₂CH₂CCl₂H,CF₃CCl₂CH₂CCl₃, CF₃CCl₂CHClCCl₂H, CF₃CCl₂CHClCCl₃, CF₃CClFCHClCCl₂H,CF₃CClFCHClCCl₃, CF₃CClFCH₂CCl₂H, CF₃CClFCH₂CCl₃, CF₃CClFCHFCCl₂H,CF₃CClFCHFCCl₃, CF₃CClHCHFCCl₂H and CF₃CClHCHFCCl₃, with HF in areaction zone in the presence of a chromium oxyfluoride catalyst toproduce a product mixture comprising an internal fluorobutene.

Also disclosed is a vapor phase process for making internalfluoropentenes comprising contacting a halopentane starting materialselected from the group consisting of CF₂HCHXCH₂CX₂CX₃, CF₃CHXCH₂CX₂CX₃,CF₃CHXCHXCX₂CX₃, CF₃CX₂CH₂CX₂CX₃, CF₃CX₂CHXCX₂CX₃ and CF₃CHXCHFCX₂CX₃,with HF in a reaction zone in the presence of a chromium oxyfluoridecatalyst to produce a product mixture comprising an internalfluoropentene, wherein each X is independently selected from the groupconsisting of F, Cl and Br, provided that not all X are fluorines.

The term “internal fluorobutene” is intended to mean a partially orfully fluorinated butene wherein the carbon-carbon double bond is not atthe terminal position. Examples of internal fluorobutenes in thisdisclosure include CF₂HCH═CHCF₂H, CF₂HCH═CHCF₃, CF₃CH═CHCF₃,CF₃CF═CHCF₂H, CF₃CH═CFCF₂H, CF₃CF═CHCF₃, CF₃CF═CFCF₂H and CF₃CF═CFCF₃.

The term “internal fluoropentene” is intended to mean a partially orfully fluorinated pentene wherein the carbon-carbon double bond is notat the terminal position. Examples of internal fluoropentenes in thisdisclosure include CF₂HCH═CHCF₂CF₃, CF₃CH═CHCF₂CF₃, CF₃CH═CFCF₂CF₃,CF₃CF═CHCF₂CF₃ and CF₃CF═CFCF₂CF₃.

The internal fluorobutenes and internal fluoropentenes of thisdisclosure exist as different configurational isomers or stereoisomers.When the specific isomer is not designated, the present disclosure isintended to include all single configurational isomers, singlestereoisomers, or any combination thereof. For instance, CF₃CH═CHCF₃ ismeant to represent the E-isomer, Z-isomer, or any combination or mixtureof both isomers in any ratio. Another example is CF₃CH═CHCF₂CF₃, bywhich is represented the E-isomer, Z-isomer, or any combination ormixture of both isomers in any ratio.

Although both E- and Z-isomers may be produced in the processes of thisdisclosure, it was found through experiments that at reaction conditionsof this disclosure CF₂HCH═CHCF₂H, CF₂HCH═CHCF₃, CF₃CH═CHCF₃,CF₃CF═CFCF₂H, CF₃CF═CFCF₃, CF₂HCH═CHCF₂CF₃, CF₃CH═CHCF₂CF₃ orCF₃CF═CFCF₂CF₃ was produced with 90 mole % or more of the E-isomer whileCF₃CH═CFCF₂CF₃, CF₃CF═CHCF₂CF₃, CF₃CF═CHCF₂H, CF₃CH═CFCF₂H orCF₃CF═CHCF₃ was produced with 90 mole % or more of the Z-isomer.

The term “halobutane” is intended to mean a butane wherein the hydrogensare partially substituted by chlorines and fluorines. A halobutanestarting material in this disclosure is selected from the groupconsisting of CF₂HCHClCH₂CCl₂H, CF₂HCHClCH₂CCl₃, CF₃CHClCH₂CCl₂H,CF₃CHClCH₂CCl₃, CF₃CHClCHClCCl₂H, CF₃CHClCHClCCl₃, CF₃CCl₂CH₂CCl₂H,CF₃CCl₂CH₂CCl₃, CF₃CCl₂CHClCCl₂H, CF₃CCl₂CHClCCl₃, CF₃CClFCHClCCl₂H,CF₃CClFCHClCCl₃, CF₃CClFCH₂CCl₂H, CF₃CClFCH₂CCl₃, CF₃CClFCHFCCl₂H,CF₃CClFCHFCCl₃, CF₃CClHCHFCCl₂H and CF₃CClHCHFCCl₃.

In one embodiment of this invention, the halobutane starting material isCF₂HCHClCH₂CCl₂H and the resulting internal fluorobutene product isCF₂HCH═CHCF₂H.

In another embodiment of this invention, the halobutane startingmaterial is CF₂HCHClCH₂CCl₃, CF₃CHClCH₂CCl₂H, or mixtures thereof, andthe resulting internal fluorobutene product is CF₃CH═CHCF₂H.

In another embodiment of this invention, the halobutane startingmaterial is CF₃CHClCH₂CCl₃ and the resulting internal fluorobuteneproduct is CF₃CH═CHCF₃.

In another embodiment of this invention, the halobutane startingmaterial is CF₃CHClCHClCCl₂H and the resulting internal fluorobuteneproduct is CF₃CF═CHCF₂H, CF₃CH═CFCF₂H, or mixtures thereof.

In another embodiment of this invention, the halobutane startingmaterial is selected from the group consisting of CF₃CHClCHClCCl₃,CF₃CCl₂CH₂CCl₃, CF₃CClHCHFCCl₃ and CF₃CClFCH₂CCl₃, and the resultinginternal fluorobutene product is CF₃CF═CHCF₃.

In another embodiment of this invention, the halobutane startingmaterial is CF₃CCl₂CH₂CCl₂H, CF₃CClFCH₂CCl₂H, or mixtures thereof, andthe resulting internal fluorobutene product is CF₃CF═CHCF₂H.

In another embodiment of this invention, the halobutane startingmaterial is selected from the group consisting of CF₃CCl₂CHClCCl₂H,CF₃CClFCHClCCl₂H and CF₃CClFCHFCCl₂H, and the resulting internalfluorobutene product is CF₃CF═CFCF₂H.

In another embodiment of this invention, the halobutane startingmaterial is selected from the group consisting of CF₃CCl₂CHClCCl₃,CF₃CClFCHClCCl₃, CF₃CClFCHFCCl₃, and the resulting internal fluorobuteneproduct is CF₃CF═CFCF₃.

In another embodiment of this invention, the halobutane startingmaterial is CF₃CClHCHFCCl₂H and the resulting internal fluorobuteneproduct is CF₃CH═CFCF₂H.

The term “halopentane” is intended to mean a pentane wherein thehydrogens are partially substituted by fluorines, chlorine(s) and/orbromine(s). A halopentane starting material in this disclosure can berepresented by the formula CF₂HCHXCH₂CX₂CX₃, CF₃CHXCH₂CX₂CX₃,CF₃CHXCHXCX₂CX₃, CF₃CX₂CH₂CX₂CX₃, CF₃CX₂CHXCX₂CX₃ or CF₃CHXCHFCX₂CX₃,wherein each X is independently selected from the group consisting of F,Cl and Br, provided that not all X are fluorines.

Examples of halopentane starting materials of the formulaCF₂HCHXCH₂CX₂CX₃ include CF₂HCHClCH₂CCl₂CCl₃, CF₂HCHClCH₂CClFCCl₃,CF₂HCHClCH₂CCl₂CF₃, CF₂HCHClCH₂CClFCF₃, CF₂HCHClCH₂CCl₂CClF₂,CF₂HCHBrCH₂CCl₂CCl₃, CF₂HCHBrCH₂CClFCCl₃, CF₂HCHBrCH₂CClBrCF₃,CF₂HCHBrCH₂CBr₂CF₃, CF₂HCHBrCH₂CBr₂CCl₃ and CF₂HCHBrCH₂CCl₂CClF₂.

Examples of halopentane starting materials of the formulaCF₃CHXCH₂CX₂CX₃ include CF₃CHClCH₂CCl₂CCl₃, CF₃CHClCH₂CClFCCl₃,CF₃CHClCH₂CCl₂CF₃, CF₃CHClCH₂CClFCF₃, CF₃CHClCH₂CCl₂CClF₂,CF₃CHBrCH₂CCl₂CCl₃, CF₃CHBrCH₂CClFCCl₃, CF₃CHBrCH₂CClBrCF₃,CF₃CHBrCH₂CBr₂CF₃, CF₃CHBrCH₂CBr₂CCl₃ and CF₃CHBrCH₂CCl₂CClF₂.

Examples of halopentane starting materials of the formulaCF₃CHXCHXCX₂CX₃ include CF₃CHClCHClCCl₂CCl₃, CF₃CHClCHClCClFCCl₃,CF₃CHClCHClCCl₂CF₃, CF₃CHClCHClCClFCF₃, CF₃CHClCHClCCl₂CClF₂,CF₃CHBrCHClCCl₂CCl₃, CF₃CHBrCHClCClFCCl₃, CF₃CHBrCHClCClBrCF₃,CF₃CHBrCHClCBr₂CF₃, CF₃CHBrCHClCBr₂CCl₃ and CF₃CHBrCHClCCl₂CClF₂.

Examples of halopentane starting materials of the formulaCF₃CX₂CH₂CX₂CX₃ include CF₃CCl₂CH₂CCl₂CCl₃, CF₃CCl₂CH₂CClFCCl₃,CF₃CCl₂CH₂CCl₂CF₃, CF₃CCl₂CH₂CClFCF₃, CF₃CCl₂CH₂CCl₂CClF₂,CF₃CCl₂CH₂CCl₂CCl₃, CF₃CClBrCH₂CClFCCl₃, CF₃CClBrCH₂CClBrCF₃,CF₃CClBrCH₂CBr₂CF₃, CF₃CClBrCH₂CBr₂CCl₃, CF₃CClBrCH₂CCl₂CClF₂,CF₃CFClCH₂CCl₂CCl₃, CF₃CFClCH₂CClFCCl₃, CF₃CFClCH₂CCl₂CF₃,CF₃CFClCH₂CClFCF₃, CF₃CFClCH2CCl₂CClF₂, CF₃CFBrCH₂CCl₂CCl₃,CF₃CFBrCH₂CClFCCl₃, CF₃CFBrCH₂CClBrCF₃, CF₃CFBrCH₂CBr₂CF₃,CF₃CFBrCH₂CBr₂CCl₃ and CF₃CFBrCH₂CCl₂CClF₂.

Examples of halopentane starting materials of the formulaCF₃CX₂CHXCX₂CX₃ include CF₃CCl₂CHClCCl₂CCl₃, CF₃CCl₂CHClCClFCCl₃,CF₃CCl₂CHClCCl₂CF₃, CF₃CCl₂CHClCClFCF₃, CF₃CCl₂CHClCCl₂CClF₂,CF₃CClBrCHClCCl₂CCl₃, CF₃CClBrCHClCClFCCl₃, CF₃CClBrCHClCClBrCF₃,CF₃CClBrCHClCBr₂CF₃, CF₃CClBrCHClCBr₂CCl₃, CF₃CClBrCHClCCl₂CClF₂,CF₃CFClCHFCCl₂CCl₃, CF₃CFClCHFCClFCCl₃, CF₃CFClCHFCCl₂CF₃,CF₃CFClCHFCClFCF₃, CF₃CFClCHFCCl₂CClF₂, CF₃CFBrCHFCCl₂CCl₃,CF₃CFBrCHFCClFCCl₃, CF₃CFBrCHFCClBrCF₃, CF₃CFBrCHFCBr₂CF₃,CF₃CFBrCHFCBr₂CCl₃ and CF₃CFBrCHFCCl₂CClF₂.

Examples of halopentane starting materials of the formulaCF₃CHXCHFCX₂CX₃ include CF₃CHClCHFCCl₂CCl₃, CF₃CHClCHFCClFCCl₃,CF₃CHClCHFCCl₂CF₃, CF₃CHClCHFCClFCF₃, CF₃CHClCHFCCl₂CClF₂,CF₃CHBrCHFCCl₂CCl₃, CF₃CHBrCHFCClFCCl₃, CF₃CHBrCHFCClBrCF₃,CF₃CHBrCHFCBr₂CF₃, CF₃CHBrCHFCBr₂CCl₃, CF₃CHBrCHFCCl₂CClF₂.

In one embodiment of this invention, the halopentane starting materialis CF₂HCHXCH₂CX₂CX₃ and the resulting internal fluoropentene product isCF₂HCH═CHCF₂CF₃.

In another embodiment of this invention, the halopentane startingmaterial is CF₃CHXCH₂CX₂CX₃ and the resulting internal fluoropenteneproduct is CF₃CH═CHCF₂CF₃.

In another embodiment of this invention, the halopentane startingmaterial is CF₃CHXCHXCX₂CX₃ and the resulting internal fluoropenteneproduct is CF₃CH═CFCF₂CF₃, CF₃CF═CHCF₂CF₃, or mixtures thereof.

In another embodiment of this invention, the halopentane startingmaterial is CF₃CX₂CH₂CX₂CX₃ and the resulting internal fluoropenteneproduct is CF₃CF═CHCF₂CF₃.

In another embodiment of this invention, the halopentane startingmaterial is CF₃CX₂CHXCX₂CX₃ and the resulting internal fluoropenteneproduct is CF₃CF═CFCF₂CF₃.

In another embodiment of this invention, the halopentane startingmaterial is CF₃CHXCHFCX₂CX₃ and the resulting internal fluoropenteneproduct is CF₃CH═CFCF₂CF₃.

Halobutane starting materials may be prepared by the processes known inthe art or disclosed in Russian Patent Application Numbers 2010147009,2010147008 and 20100147002 [FL1564, FL1565 and FL1388] filedconcurrently herewith, and hereby incorporated by reference in theirentirety.

Halopentane starting materials may be prepared by the processes known inthe art or disclosed in Russian Patent Application Numbers 2010147009,2010147008 and 20100147002 [FL1564, FL1565 and FL1388] filedconcurrently herewith, and hereby incorporated by reference in theirentirety.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

Also, use of “a” or “an” are employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one or at least one and the singular alsoincludes the plural unless it is obvious that it is meant otherwise.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of embodiments of the present invention, suitablemethods and materials are described below. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety, unless a particular passageis cited. In case of conflict, the present specification, includingdefinitions, will control. In addition, the materials, methods, andexamples are illustrative only and not intended to be limiting.

The processes of this disclosure use a molar ratio of HF to thehalobutane or halopentane starting material that is at leaststoichiometric. The stoichiometric amount is the total number of Cland/or Br substituents on the halobutane or halopentane startingmaterials minus one. For example, the stoichiometric ratio of HF toCF₃CHClCH₂CCl₂CF₃ is 2:1. As another example, the stoichiometric ratioof HF to CF₂HCHBrCH₂CCl₂CCl₃ is 5:1.

The molar ratio of HF to the halobutane or halopentane starting materialis typically from about the stoichiometric amount to about 50:1. In someembodiments of this invention, the molar ratio of HF to the halobutaneor halopentane starting material is from about twice the stoichiometricamount to about 30:1. In some embodiments of this invention, the molarratio of HF to the halobutane or halopentane starting material is fromabout twice the stoichiometric amount to about 20:1.

The term “a chromium oxyfluoride catalyst” is intended to mean achromium oxyfluoride represented by formula Cr₂O_(x)F_(y) whereinx+y/2=3.

The term “amorphous” is intended to mean that there is no substantialpeak in a X-ray diffraction pattern of the subject solid.

The chromium oxyfluoride catalysts can be made by treating Cr₂O₃ withHF, CCl₃F, COF₂ or hydrofluorocarbons. In one embodiment of thisinvention, a chromium oxyfluoride catalyst is made by treating dry Cr₂O₃with a fluorination agent such as CCl₃F or HF. This treatment can beaccomplished by placing the dry Cr₂O₃ in a suitable container (which canbe the reactor to be used to perform the subsequent catalyticalreaction) and thereafter passing HF over the dry Cr₂O₃ for a suitableperiod of time (e.g., about 15 to about 800 minutes) at a suitabletemperature (e.g., about 200° C. to about 450° C.), such as whatdescribed in Example 1.

In another embodiment of this invention, a chromium oxyfluoride catalystis made by treating Cr₂O₃ with a hydrofluorocarbon at an elevatedtemperature.

In another embodiment of this invention, a chromium oxyfluoride catalystis made in situ. For example, the starting material CF₃CHClCHFCClFCCl₃,CF₃CHClCHFCCl₂CF₃ or CF₃CHClCHFCClFCF₃ can be employed in the formationof a chromium oxyfluoride catalyst by heating it together with Cr₂O₃ inthe reactor.

Cr₂O₃ is commercially available from BASF Catalysts LLC, 25 MiddlesexEssex Tumpike, Iselin, N.J. 08830-0770.

Cr₂O₃ can also be prepared by reducing chromium (VI) oxide in water witha suitable reducing agent, such as ethanol, as disclosed in U.S. Pat.No. 3,258,500, which is incorporated herein by reference. Of note is theso-called gel-type activated Cr₂O₃ obtained by reducing chromiumtrioxide (CrO₃) and dehydrating the reduced product in the mannerdisclosed by Ruthruff in “Inorganic Synthesis”, Vol. II, pp. 190-193,published in 1946 by McGraw-Hill Book Co., New York, and by Turkevichand Ruthruff in U.S. Pat. No. 2,271,356, both of which are incorporatedherein by reference. In one embodiment of this invention, Cr₂O₃ isprepared by dissolving chromium trioxide in water, gradually addingethanol or other suitable reducing agent to the solution and heatingunder reflux conditions until the Cr₂O₃ gel precipitates, separating thegel from the reaction mixture, drying it, and then dehydrating andactivating the product by heating it at a temperature of from about 400°C. to about 600° C. in an inert atmosphere until the water is removedand an anhydrous product is obtained.

Cr₂O₃ can also be prepared by pyrolysis of ammonium dichromate((NH₄)₂Cr₂O₇) as disclosed in U.S. Pat. No. 5,036,036, which isincorporated herein by reference. Of note is Cr₂O₃ prepared bypyrolysing ammonium dichromate and treating (e.g., washing withdeionized water) the resulting Cr₂O₃ to reduce the alkali metal contentto 100 ppm or less. Also of note is Cr₂O₃ prepared by first treatingammonium dichromate containing 60-2000 ppm alkali metal to reduce itsalkali metal content to less than 60 ppm and then pyrolysing theresulting ammonium dichromate with reduced alkali metal content to formCr₂O₃ containing 100 ppm or less of alkali metal content.

Cr₂O₃ can also be prepared by the reaction of chromium (VI) oxide with areducing solvent, such as methanol, as disclosed in U.S. Pat. No.4,828,818, which is incorporated herein by reference.

The amount of potassium and other alkali metals in Cr₂O₃ can be reducedby a water washing step as disclosed in U.S. Pat. No. 5,036,036.

In one embodiment of this invention, the chromium oxyfluoride catalysthas surface area of from about 10 m²/g to about 800 m²/g.

In another embodiment of this invention, the chromium oxyfluoridecatalyst has surface area of from about 20 m²/g to about 400 m²/g.

In another embodiment of this invention, the chromium oxyfluoridecatalyst has surface area of from about 40 m²/g to about 300 m²/g.

In one embodiment of this invention, the chromium oxyfluoride catalystcontains an alkali metal content of about 2000 ppm or less.

In another embodiment of this invention, the chromium oxyfluoridecatalyst contains an alkali metal content of about 300 ppm or less.

In another embodiment of this invention, the chromium oxyfluoridecatalyst contains an alkali metal content of about 100 ppm or less.

In one embodiment of this invention, the chromium oxyfluoride catalystis amorphous.

In another embodiment of this invention, the chromium oxyfluoridecatalyst is prepared from crystalline α-Cr₂O₃.

The form of the catalyst is not critical and may be used as pellets,powders or granules.

The temperature employed in the reaction zone for the catalyticalreactions of this disclosure typically ranges from about 200° C. toabout 500° C. In some embodiments of this invention, the temperatureemployed in the reaction zone for the catalytical reactions ranges fromabout 300° C. to about 400° C.

The contacting time of the halobutane or halopentane starting materialwith HF in the reaction zone in the presence of the chromium oxyfluoridecatalyst is not critical and typically ranges from about 0.1 second toabout 1000 seconds. In some embodiments of this invention, thecontacting time ranges from about 5 seconds to about 100 seconds.

The pressure in the reaction zone for the catalytical reactions of thisdisclosure can be subatmospheric, atmospheric or superatmospheric. Insome embodiments of this invention, the pressure in the reaction zone isnear atmospheric.

Optionally, the catalytical reactions of this disclosure can beconducted in the presence of oxygen. In some embodiments of thisinvention, the catalytical reactions are conducted in the presence ofair. In some embodiments of this invention, air is co-fed with thestarting materials (halobutane, halopentane, HF, halobutane/HF mixturesor halopentane/HF mixtures) into the reaction zone.

Optionally, the catalytical reactions of this disclosure can beconducted in the presence of inert gases such as nitrogen, helium,argon, or their mixtures thereof. In some embodiments of this invention,the inert gas is co-fed with the starting materials (halobutane,halopentane, HF, halobutane/HF mixtures or halopentane/HF mixtures) intothe reaction zone. In some embodiments of this invention, the inert gasis nitrogen.

In some embodiments of this invention, the desired internal fluorobuteneor internal fluoropentene product may be recovered from the productmixture by fractional distillation.

The reactors, distillation columns, and their associated feed lines,effluent lines, and associated units used in applying the processes ofembodiments of this invention should be constructed of materialsresistant to corrosion. Typical materials of construction includestainless steels, in particular of the austenitic type, the well-knownhigh nickel alloys, such as Monel™ nickel-copper alloys, Hastelloy™nickel-based alloys and, Inconel™ nickel-chromium alloys, andcopper-clad steel.

Many aspects and embodiments have been described above and are merelyexemplary and not limiting. After reading this specification, skilledartisans appreciate that other aspects and embodiments are possiblewithout departing from the scope of the invention.

EXAMPLES

The concepts described herein will be further described in the followingexamples, which do not limit the scope of the invention described in theclaims.

Example 1

Example 1 demonstrates a method for preparing the chromium oxyfluoridecatalyst.

6 cc (cubic centimeter) (7.3 gm) of Cr₂O₃ gel pellets prepared accordingto the process described in U.S. Pat. No. 3,258,500, Example 1(A), werecrushed and sieved to 12/20 mesh, and filled into an Inconel™ tube (⅝inch OD) to form a catalyst bed. The Cr₂O₃ was heated to 400° C. under apurge of nitrogen (38 sccm (standard cubic centimeters per minute)) for120 minutes and then at 300° C. for 80 minutes while continuing thenitrogen purge. Then the nitrogen flow was reduced to 28 sccm and HF wasfed into the tube at 9 sccm for 45 minutes. While maintaining HF andnitrogen flows, the temperature was raised to 325° C. for 80 minutes, to350° C. for 80 minutes, 375° C. for 200 minutes, 400° C. for 40 minutes,and 425° C. for 55 minutes. While keeping the temperature at 400° C.,the flow of nitrogen was lowered to 19 sccm and the flow of HF wasraised to 15 sccm for 25 minutes. The flow of nitrogen was then loweredto 11 sccm and the flow of HF was raised to 21 sccm for 30 minutes. Theflow of nitrogen was then lowered to 4 sccm and the flow of HF wasraised to 27 sccm for 30 minutes. The flow of nitrogen was thendiscontinued and the flow of HF was raised to 30 sccm for 160 minutes.

Example 2

Example 2 demonstrates that CF₃CHClCH₂CCl₂CF₃ can react with HF in thepresence of a chromium oxyfluoride catalyst to produce CF₃CH═CHCF₂CF₃.

The chromium oxyfluoride catalyst prepared in Example 1 was used here.After the HF treatment in Example 1, the tube temperature was lowered to348° C. and stabilized. CF₃CHClCH₂CCl₂CF₃ was fed into a vaporizer at0.55 ml/hour and was vaporized at 140° C. Nitrogen was flowed throughthe vaporizer at 3 sccm and carried the vaporized CF₃CHClCH₂CCl₂CF₃ tothe tube while HF was flowed through the tube at 8.3 sccm. Part of thereactor tube effluent was analyzed by on line GC/MS. The analyticalresult after three hours of continuous operation was shown in Table 1below.

TABLE 1 Component Mole percent CCl₂FCF₃ 0.9% CF₃CH═CFCF₂CF₃ 3.2%E-CF₃CH═CHCF₂CF₃ 42.6% C₅HClF₈ isomers 18.2% C₅H₂ClF₇ isomer 1 3.5%C₅H₂ClF₇ isomer 2 1.1% C₅H₂ClF₇ isomer 3 1.1% CF₃CH═CHCHClCF₃ 6.2%CF₃CH═CHCCl₂CF₃ 16.2% Unknowns 7.0%

Example 3

Example 3 also demonstrates that CF₃CHClCH₂CCl₂CF₃ can react with HF inthe presence of a chromium oxyfluoride catalyst to produceCF₃CH═CHCF₂CF₃.

Another batch of chromium oxyfluoride catalyst was prepared according toExample 1 by using 7.2 gm of Cr₂O₃ gel pellets. The tube temperature waslowered to 323° C. and stabilized. CF₃CHClCH₂CCl₂CF₃ was fed into avaporizer at 0.55 ml/hour and was vaporized at 140° C. Nitrogen wasflowed through the vaporizer at 3 sccm and carried the vaporizedCF₃CHClCH₂CCl₂CF₃ to the tube while HF was flowed through the tube at8.3 sccm. Part of the reactor tube effluent was analyzed by on lineGC/MS. The analytical result after one hour of continuous operation wasshown in Table 2 below.

TABLE 2 Component Mole percent CCl₂FCF₃ 0.3% CF₃CH═CFCF₂CF₃ 1.3%E-CF₃CH═CHCF₂CF₃ 52.1% C₅HClF₈ isomers 17.9% C₅H₂ClF₇ isomer 1 2.5%C₅H₂ClF₇ isomer 2 0.8% C₅H₂ClF₇ isomer 3 0.7% CF₃CH═CHCHClCF₃ 0.1%CF₃CH═CHCCl₂CF₃ 19.0% Unknowns 5.3%

Example 4

Example 4 demonstrates that CF₃CHClCH₂CHCl₂ can react with HF in thepresence of a chromium oxyfluoride catalyst to produce CF₃CH═CHCHF₂.

Another batch of chromium oxyfluoride catalyst was prepared according toExample 1 by using 7.4 gm of Cr₂O₃ gel pellets. The tube temperature waslowered to 323° C. and stabilized. CF₃CHClCH₂CHCl₂ was fed into avaporizer at 0.60 ml/hour and was vaporized at 150° C. Nitrogen wasflowed through the vaporizer at 2 sccm and carried the vaporizedCF₃CHClCH₂CHCl₂ to the tube while HF was flowed through the tube at 20.4sccm. Part of the reactor tube effluent was analyzed by on line GC/MS.The analytical result after six hours of continuous operation was shownin Table 3 below.

TABLE 3 Component Mole percent E-CF₃CH═CHCF₃ 6.5% E-CF₃CH═CHCHF₂ 83.2%E-CF₃CH═CHCF₃ 0.1% CF₃CHClCH₂CF₃ 0.3% CF₃CHClCH₂CHF₂ 1.8% Unknowns 8.1%

Example 5

Example 5 demonstrates that CF₃CF₂CHClCH₂CCl₃ can react with HF in thepresence of a chromium oxyfluoride catalyst to produce CF₃CH═CHCF₂CF₃.

Another batch of chromium oxyfluoride catalyst was prepared according toExample 1 by using 7.32 gm of Cr₂O₃ gel pellets. The tube temperaturewas lowered to 273° C. and stabilized. CF₃CF₂CHClCH₂CCl₃ was fed into avaporizer at 0.82 ml/hour and was vaporized at 165° C. Nitrogen wasflowed through the vaporizer at 4 sccm and carried the vaporizedCF₃CF₂CHClCH₂CCl₃ to the tube while HF was flowed through the tube at11.8 sccm. Part of the reactor tube effluent was analyzed by on lineGC/MS. The analytical result after six hours of continuous operation wasshown in Table 4 below.

TABLE 4 Component Mole percent E-CF₃CH═CHCF₂CF₃ 71.0% CF₃CF═CHCF₂CF₃0.7% E-CF₃CH═CHCF₂CF₃ 0.2% CF₃CH═CClCF₃ 0.2% CCl₂FCClF₂ 0.5%CF₃CCl═CHCF₂CF₃ 9.0% CF₂ClCH═CHCF₂CF₃ 3.7% CFCl₂CH═CHCF₂CF₃ 7.5%Unknowns 7.2%

Example 6

Example 6 demonstrates that CF₃CFClCH₂CCl₃ can react with HF in thepresence of a chromium oxyfluoride catalyst to produce CF₃CH═CFCF₃.

The same batch of catalyst as in the Example 5 was used here. The tubetemperature was raised to 302° C. and stabilized. CF₃CFClCH₂CCl₃ was fedinto a vaporizer at 0.92 ml/hour and was vaporized at 160° C. Nitrogenwas flowed through the vaporizer at 3.7 sccm and carried the vaporizedCF₃CFClCH₂CCl₃ to the tube while HF was flowed through the tube at 10.0sccm. Part of the reactor tube effluent was analyzed by on line GC/MS.The analytical result after fourteen hours of continuous operation wasshown in Table 5 below.

TABLE 5 Component Mole percent Z—CF₃CH═CFCF₃ 14.8% CF₃CH₂CF₂CF₃ 11.5%E-CF₃CH═CClCF₃ 70.4% Z—CF₃CH═CClCF₃ 2.8% Unknowns 0.5%

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed are not necessarily the order inwhich they are performed.

In the foregoing specification, the concepts have been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the invention as set forth in theclaims below. Accordingly, the specification is to be regarded in anillustrative rather than a restrictive sense, and all such modificationsare intended to be included within the scope of invention.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

It is to be appreciated that certain features are, for clarity,described herein in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.Further, reference to values stated in ranges include each and everyvalue within that range.

1. A vapor phase process for making internal fluorobutenes comprisingcontacting a halobutane starting material selected from the groupconsisting of CF₂HCHClCH₂CCl₂H, CF₂HCHClCH₂CCl₃, CF₃CHClCH₂CCl₂H,CF₃CHClCH₂CCl₃, CF₃CHClCHClCCl₂H, CF₃CHClCHClCCl₃, CF₃CCl₂CH₂CCl₂H,CF₃CCl₂CH₂CCl₃, CF₃CCl₂CHClCCl₂H, CF₃CCl₂CHClCCl₃, CF₃CClFCHClCCl₂H,CF₃CClFCHClCCl₃, CF₃CClFCH₂CCl₂H, CF₃CClFCH₂CCl₃, CF₃CClFCHFCCl₂H,CF₃CClFCHFCCl₃, CF₃CClHCHFCCl₂H and CF₃CClHCHFCCl₃, with HF in areaction zone in the presence of a chromium oxyfluoride catalyst toproduce a product mixture comprising an internal fluorobutene.
 2. Thevapor phase process of claim 1 wherein said halobutane starting materialis CF₂HCHClCH₂CCl₂H and said internal fluorobutene product isCF₂HCH═CHCF₂H.
 3. (canceled)
 4. The vapor phase process of claim 1wherein said halobutane starting material is CF₃CHClCH₂CCl₃ and saidinternal fluorobutene product is CF₃CH═CHCF₃.
 5. The vapor phase processof claim 1 wherein said halobutane starting material is CF₃CHClCHClCCl₂Hand said internal fluorobutene product is CF₃CF═CHCF₂H, CF₃CH═CFCF₂H, ormixtures thereof.
 6. The vapor phase process of claim 1 wherein saidhalobutane starting material is selected from the group consisting ofCF₃CHClCHClCCl₃, CF₃CCl₂CH₂CCl₃, CF₃CClHCHFCCl₃ and CF₃CClFCH₂CCl₃, andsaid internal fluorobutene product is CF₃CF═CHCF₃.
 7. The vapor phaseprocess of claim 1 wherein said halobutane starting material isCF₃CCl₂CH₂CCl₂H, CF₃CClFCH₂CCl₂H, or mixtures thereof, and said internalfluorobutene product is CF₃CF═CHCF₂H.
 8. The vapor phase process ofclaim 1 wherein said halobutane starting material is selected from thegroup consisting of CF₃CCl₂CHClCCl₂H, CF₃CClFCHClCCl₂H andCF₃CClFCHFCCl₂H, and said internal fluorobutene product is CF₃CF═CFCF₂H.9. The vapor phase process of claim 1 wherein said halobutane startingmaterial is selected from the group consisting of CF₃CCl₂CHClCCl₃,CF₃CClFCHClCCl₃, CF₃CClFCHFCCl₃, and said internal fluorobutene productis CF₃CF═CFCF₃.
 10. The vapor phase process of claim 1 wherein saidhalobutane starting material is CF₃CClHCHFCCl₂H and said internalfluorobutene product is CF₃CH═CFCF₂H.
 11. A vapor phase process formaking internal fluoropentenes comprising contacting a halopentanestarting material selected from the group consisting ofCF₂HCHXCH₂CX₂CX₃, CF₃CHXCH₂CX₂CX₃, CF₃CHXCHXCX₂CX₃, CF₃CX₂CH₂CX₂CX₃,CF₃CX₂CHXCX₂CX₃ and CF₃CHXCHFCX₂CX₃, with HF in a reaction zone in thepresence of a chromium oxyfluoride catalyst to produce a product mixturecomprising an internal fluoropentene, wherein each X is independentlyselected from the group consisting of F, Cl and Br, provided that notall X are fluorines.
 12. The vapor phase process of claim 11 whereinsaid halopentane starting material is CF₂HCHXCH₂CX₂CX₃ and said internalfluoropentene product is CF₂HCH═CHCF₂CF₃.
 13. The vapor phase process ofclaim 12 wherein said halopentane starting material is selected from thegroup consisting of CF₂HCHClCH₂CCl₂CCl₃, CF₂HCHClCH₂CClFCCl₃,CF₂HCHClCH₂CCl₂CF₃, CF₂HCHClCH₂CClFCF₃, CF₂HCHClCH₂CCl₂CClF₂,CF₂HCHBrCH₂CCl₂CCl₃, CF₂HCHBrCH₂CClFCCl₃, CF₂HCHBrCH₂CClBrCF₃,CF₂HCHBrCH₂CBr₂CF₃, CF₂HCHBrCH₂CBr₂CCl₃ and CF₂HCHBrCH₂CCl₂CClF₂. 14.The vapor phase process of claim 11 wherein said halopentane startingmaterial is CF₃CHXCH₂CX₂CX₃ and said internal fluoropentene product isCF₃CH═CHCF₂CF₃.
 15. The vapor phase process of claim 14 wherein saidhalopentane starting material is selected from the group consisting ofCF₃CHClCH₂CCl₂CCl₃, CF₃CHClCH₂CClFCCl₃, CF₃CHClCH₂CCl₂CF₃,CF₃CHClCH₂CClFCF₃, CF₃CHClCH₂CCl₂CClF₂, CF₃CHBrCH₂CCl₂CCl₃,CF₃CHBrCH₂CClFCCl₃, CF₃CHBrCH₂CClBrCF₃, CF₃CHBrCH₂CBr₂CF₃,CF₃CHBrCH₂CBr₂CCl₃ and CF₃CHBrCH₂CCl₂CClF₂.
 16. The vapor phase processof claim 11 wherein said halopentane starting material isCF₃CHXCHXCX₂CX₃ and said internal fluoropentene product isCF₃CH═CFCF₂CF₃, CF₃CF═CHCF₂CF₃, or mixtures thereof.
 17. The vapor phaseprocess of claim 16 wherein said halopentane starting material isselected from the group consisting of CF₃CHClCHClCCl₂CCl₃,CF₃CHClCHClCClFCCl₃, CF₃CHClCHClCCl₂CF₃, CF₃CHClCHClCClFCF₃,CF₃CHClCHClCCl₂CClF₂, CF₃CHBrCHClCCl₂CCl₃, CF₃CHBrCHClCClFCCl₃,CF₃CHBrCHClCClBrCF₃, CF₃CHBrCHClCBr₂CF₃, CF₃CHBrCHClCBr₂CCl₃ andCF₃CHBrCHClCCl2CClF₂.
 18. The vapor phase process of claim 11 whereinsaid halopentane starting material is CF₃CX₂CH₂CX₂CX₃ and said internalfluoropentene product is CF₃CF═CHCF₂CF₃.
 19. The vapor phase process ofclaim 18 wherein said halopentane starting material is selected from thegroup consisting of CF₃CCl₂CH₂CCl₂CCl₃, CF₃CCl₂CH₂CClFCCl₃,CF₃CCl₂CH₂CCl₂CF₃, CF₃CCl₂CH₂CClFCF₃, CF₃CCl₂CH₂CCl₂CClF₂,CF₃CCl₂CH₂CCl₂CCl₃, CF₃CClBrCH₂CClFCCl₃, CF₃CClBrCH₂CClBrCF₃,CF₃CClBrCH₂CBr₂CF₃, CF₃CClBrCH₂CBr₂CCl₃, CF₃CClBrCH₂CCl₂CClF₂,CF₃CFClCH₂CCl₂CCl₃, CF₃CFClCH₂CClFCCl₃, CF₃CFClCH₂CCl₂CF₃,CF₃CFClCH₂CClFCF₃, CF₃CFClCH₂CCl₂CClF₂, CF₃CFBrCH₂CCl₂CCl₃,CF₃CFBrCH₂CClFCCl₃, CF₃CFBrCH₂CClBrCF₃, CF₃CFBrCH₂CBr₂CF₃,CF₃CFBrCH₂CBr₂CCl₃ and CF₃CFBrCH₂CCl₂CClF₂.
 20. The vapor phase processof claim 11 wherein said halopentane starting material isCF₃CX₂CHXCX₂CX₃ and said internal fluoropentene product isCF₃CF═CFCF₂CF₃.
 21. (canceled)
 22. The vapor phase process of claim 11wherein said halopentane starting material is CF₃CHXCHFCX₂CX₃ and saidinternal fluoropentene product is CF₃CH═CFCF₂CF₃.
 23. (canceled) 24.(canceled)
 25. (canceled)
 26. (canceled)
 27. (canceled)
 28. (canceled)